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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
commit43a97878ce14b72f0981164f87f2e35e14151312 (patch)
tree620249daf56c0258faa40cbdcf9cfba06de2a846 /js/src/gc/Statistics.h
parentInitial commit. (diff)
downloadfirefox-upstream.tar.xz
firefox-upstream.zip
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/src/gc/Statistics.h')
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef gc_Statistics_h
+#define gc_Statistics_h
+
+#include "mozilla/Array.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/EnumeratedArray.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/TimeStamp.h"
+
+#include "jspubtd.h"
+#include "NamespaceImports.h"
+
+#include "gc/GCEnum.h"
+#include "js/AllocPolicy.h"
+#include "js/GCAPI.h"
+#include "js/SliceBudget.h"
+#include "js/Vector.h"
+
+namespace js {
+
+class JSONPrinter;
+
+namespace gcstats {
+
+// Phase data is generated by a script. If you need to add phases, edit
+// js/src/gc/GenerateStatsPhases.py
+
+#include "gc/StatsPhasesGenerated.h"
+
+// Counts can be incremented with Statistics::count(). They're reset at the end
+// of a Major GC.
+enum Count {
+ COUNT_NEW_CHUNK,
+ COUNT_DESTROY_CHUNK,
+ COUNT_MINOR_GC,
+
+ // Number of times a 'put' into a storebuffer overflowed, triggering a
+ // compaction
+ COUNT_STOREBUFFER_OVERFLOW,
+
+ // Number of arenas relocated by compacting GC.
+ COUNT_ARENA_RELOCATED,
+
+ // Number of cells marked during the marking phase. Excludes atoms marked when
+ // not collecting the atoms zone.
+ COUNT_CELLS_MARKED,
+
+ COUNT_LIMIT
+};
+
+// Stats can be set with Statistics::setStat(). They're not reset automatically.
+enum Stat {
+ // Number of strings tenured.
+ STAT_STRINGS_TENURED,
+
+ // Number of strings deduplicated.
+ STAT_STRINGS_DEDUPLICATED,
+
+ // Number of realms that had nursery strings disabled due to large numbers
+ // being tenured.
+ STAT_NURSERY_STRING_REALMS_DISABLED,
+
+ // Number of BigInts tenured.
+ STAT_BIGINTS_TENURED,
+
+ // Number of realms that had nursery BigInts disabled due to large numbers
+ // being tenured.
+ STAT_NURSERY_BIGINT_REALMS_DISABLED,
+
+ STAT_LIMIT
+};
+
+struct ZoneGCStats {
+ /* Number of zones collected in this GC. */
+ int collectedZoneCount = 0;
+
+ /* Total number of zones in the Runtime at the start of this GC. */
+ int zoneCount = 0;
+
+ /* Number of zones swept in this GC. */
+ int sweptZoneCount = 0;
+
+ /* Total number of compartments in all zones collected. */
+ int collectedCompartmentCount = 0;
+
+ /* Total number of compartments in the Runtime at the start of this GC. */
+ int compartmentCount = 0;
+
+ /* Total number of compartments swept by this GC. */
+ int sweptCompartmentCount = 0;
+
+ ZoneGCStats() = default;
+};
+
+struct Trigger {
+ size_t amount = 0;
+ size_t threshold = 0;
+};
+
+#define FOR_EACH_GC_PROFILE_TIME(_) \
+ _(BeginCallback, "bgnCB", PhaseKind::GC_BEGIN) \
+ _(MinorForMajor, "evct4m", PhaseKind::EVICT_NURSERY_FOR_MAJOR_GC) \
+ _(WaitBgThread, "waitBG", PhaseKind::WAIT_BACKGROUND_THREAD) \
+ _(Prepare, "prep", PhaseKind::PREPARE) \
+ _(Mark, "mark", PhaseKind::MARK) \
+ _(Sweep, "sweep", PhaseKind::SWEEP) \
+ _(Compact, "cmpct", PhaseKind::COMPACT) \
+ _(EndCallback, "endCB", PhaseKind::GC_END) \
+ _(MinorGC, "minor", PhaseKind::MINOR_GC) \
+ _(EvictNursery, "evict", PhaseKind::EVICT_NURSERY)
+
+const char* ExplainAbortReason(GCAbortReason reason);
+
+/*
+ * Struct for collecting timing statistics on a "phase tree". The tree is
+ * specified as a limited DAG, but the timings are collected for the whole tree
+ * that you would get by expanding out the DAG by duplicating subtrees rooted
+ * at nodes with multiple parents.
+ *
+ * During execution, a child phase can be activated multiple times, and the
+ * total time will be accumulated. (So for example, you can start and end
+ * PhaseKind::MARK_ROOTS multiple times before completing the parent phase.)
+ *
+ * Incremental GC is represented by recording separate timing results for each
+ * slice within the overall GC.
+ */
+struct Statistics {
+ template <typename T, size_t Length>
+ using Array = mozilla::Array<T, Length>;
+
+ template <typename IndexType, IndexType SizeAsEnumValue, typename ValueType>
+ using EnumeratedArray =
+ mozilla::EnumeratedArray<IndexType, SizeAsEnumValue, ValueType>;
+
+ using TimeDuration = mozilla::TimeDuration;
+ using TimeStamp = mozilla::TimeStamp;
+
+ // Create types for tables of times, by phase and phase kind.
+ using PhaseTimes = EnumeratedArray<Phase, Phase::LIMIT, TimeDuration>;
+ using PhaseKindTimes =
+ EnumeratedArray<PhaseKind, PhaseKind::LIMIT, TimeDuration>;
+
+ using PhaseTimeStamps = EnumeratedArray<Phase, Phase::LIMIT, TimeStamp>;
+
+ [[nodiscard]] static bool initialize();
+
+ explicit Statistics(gc::GCRuntime* gc);
+ ~Statistics();
+
+ Statistics(const Statistics&) = delete;
+ Statistics& operator=(const Statistics&) = delete;
+
+ void beginPhase(PhaseKind phaseKind);
+ void endPhase(PhaseKind phaseKind);
+ void recordParallelPhase(PhaseKind phaseKind, TimeDuration duration);
+
+ // Occasionally, we may be in the middle of something that is tracked by
+ // this class, and we need to do something unusual (eg evict the nursery)
+ // that doesn't normally nest within the current phase. Suspend the
+ // currently tracked phase stack, at which time the caller is free to do
+ // other tracked operations.
+ //
+ // This also happens internally with the PhaseKind::MUTATOR "phase". While in
+ // this phase, any beginPhase will automatically suspend the non-GC phase,
+ // until that inner stack is complete, at which time it will automatically
+ // resume the non-GC phase. Explicit suspensions do not get auto-resumed.
+ void suspendPhases(PhaseKind suspension = PhaseKind::EXPLICIT_SUSPENSION);
+
+ // Resume a suspended stack of phases.
+ void resumePhases();
+
+ void beginSlice(const ZoneGCStats& zoneStats, JS::GCOptions options,
+ const SliceBudget& budget, JS::GCReason reason,
+ bool budgetWasIncreased);
+ void endSlice();
+
+ [[nodiscard]] bool startTimingMutator();
+ [[nodiscard]] bool stopTimingMutator(double& mutator_ms, double& gc_ms);
+
+ // Note when we sweep a zone or compartment.
+ void sweptZone() { ++zoneStats.sweptZoneCount; }
+ void sweptCompartment() { ++zoneStats.sweptCompartmentCount; }
+
+ void reset(GCAbortReason reason) {
+ MOZ_ASSERT(reason != GCAbortReason::None);
+ if (!aborted) {
+ slices_.back().resetReason = reason;
+ }
+ }
+
+ void measureInitialHeapSize();
+
+ void nonincremental(GCAbortReason reason) {
+ MOZ_ASSERT(reason != GCAbortReason::None);
+ nonincrementalReason_ = reason;
+ log("Non-incremental reason: %s", nonincrementalReason());
+ }
+
+ bool nonincremental() const {
+ return nonincrementalReason_ != GCAbortReason::None;
+ }
+
+ const char* nonincrementalReason() const {
+ return ExplainAbortReason(nonincrementalReason_);
+ }
+
+ void count(Count s) { counts[s]++; }
+ void addCount(Count s, uint32_t count) { counts[s] += count; }
+
+ uint32_t getCount(Count s) const { return uint32_t(counts[s]); }
+
+ void setStat(Stat s, uint32_t value) { stats[s] = value; }
+
+ uint32_t getStat(Stat s) const { return stats[s]; }
+
+ void recordTrigger(size_t amount, size_t threshold) {
+ recordedTrigger = mozilla::Some(Trigger{amount, threshold});
+ }
+ bool hasTrigger() const { return recordedTrigger.isSome(); }
+
+ void noteNurseryAlloc() { allocsSinceMinorGC.nursery++; }
+
+ // tenured allocs don't include nursery evictions.
+ void setAllocsSinceMinorGCTenured(uint32_t allocs) {
+ allocsSinceMinorGC.tenured = allocs;
+ }
+
+ uint32_t allocsSinceMinorGCNursery() { return allocsSinceMinorGC.nursery; }
+
+ uint32_t allocsSinceMinorGCTenured() { return allocsSinceMinorGC.tenured; }
+
+ uint32_t* addressOfAllocsSinceMinorGCNursery() {
+ return &allocsSinceMinorGC.nursery;
+ }
+
+ void beginNurseryCollection(JS::GCReason reason);
+ void endNurseryCollection(JS::GCReason reason);
+
+ TimeStamp beginSCC();
+ void endSCC(unsigned scc, TimeStamp start);
+
+ UniqueChars formatCompactSliceMessage() const;
+ UniqueChars formatCompactSummaryMessage() const;
+ UniqueChars formatDetailedMessage() const;
+
+ JS::GCSliceCallback setSliceCallback(JS::GCSliceCallback callback);
+ JS::GCNurseryCollectionCallback setNurseryCollectionCallback(
+ JS::GCNurseryCollectionCallback callback);
+
+ TimeDuration clearMaxGCPauseAccumulator();
+ TimeDuration getMaxGCPauseSinceClear();
+
+ PhaseKind currentPhaseKind() const;
+
+ static const size_t MAX_SUSPENDED_PHASES = MAX_PHASE_NESTING * 3;
+
+ struct SliceData {
+ SliceData(const SliceBudget& budget, mozilla::Maybe<Trigger> trigger,
+ JS::GCReason reason, TimeStamp start, size_t startFaults,
+ gc::State initialState);
+
+ SliceBudget budget;
+ JS::GCReason reason = JS::GCReason::NO_REASON;
+ mozilla::Maybe<Trigger> trigger;
+ gc::State initialState = gc::State::NotActive;
+ gc::State finalState = gc::State::NotActive;
+ GCAbortReason resetReason = GCAbortReason::None;
+ TimeStamp start;
+ TimeStamp end;
+ size_t startFaults = 0;
+ size_t endFaults = 0;
+ PhaseTimes phaseTimes;
+ PhaseKindTimes totalParallelTimes;
+ PhaseKindTimes maxParallelTimes;
+
+ TimeDuration duration() const { return end - start; }
+ bool wasReset() const { return resetReason != GCAbortReason::None; }
+ };
+
+ typedef Vector<SliceData, 8, SystemAllocPolicy> SliceDataVector;
+
+ const SliceDataVector& slices() const { return slices_; }
+
+ const SliceData* lastSlice() const {
+ if (slices_.length() == 0) {
+ return nullptr;
+ }
+
+ return &slices_.back();
+ }
+
+ TimeStamp start() const { return slices_[0].start; }
+
+ TimeStamp end() const { return slices_.back().end; }
+
+ TimeStamp creationTime() const { return creationTime_; }
+
+ TimeDuration totalGCTime() const { return totalGCTime_; }
+ size_t initialCollectedBytes() const { return preCollectedHeapBytes; }
+
+ // File to write profiling information to, either stderr or file specified
+ // with JS_GC_PROFILE_FILE.
+ FILE* profileFile() const { return gcProfileFile; }
+
+ // Occasionally print header lines for profiling information.
+ void maybePrintProfileHeaders();
+
+ // Print header line for profile times.
+ void printProfileHeader();
+
+ // Print total profile times on shutdown.
+ void printTotalProfileTimes();
+
+ // These JSON strings are used by the firefox profiler to display the GC
+ // markers.
+
+ // Return JSON for a whole major GC
+ UniqueChars renderJsonMessage() const;
+
+ // Return JSON for the timings of just the given slice.
+ UniqueChars renderJsonSlice(size_t sliceNum) const;
+
+ // Return JSON for the previous nursery collection.
+ UniqueChars renderNurseryJson() const;
+
+#ifdef DEBUG
+ // Print a logging message.
+ void log(const char* fmt, ...);
+#else
+ void log(const char* fmt, ...){};
+#endif
+
+ private:
+ gc::GCRuntime* const gc;
+
+ /* File used for MOZ_GCTIMER output. */
+ FILE* gcTimerFile;
+
+ /* File used for JS_GC_DEBUG output. */
+ FILE* gcDebugFile;
+
+ /* File used for JS_GC_PROFILE output. */
+ FILE* gcProfileFile;
+
+ ZoneGCStats zoneStats;
+
+ JS::GCOptions gcOptions;
+
+ GCAbortReason nonincrementalReason_;
+
+ SliceDataVector slices_;
+
+ /* Most recent time when the given phase started. */
+ PhaseTimeStamps phaseStartTimes;
+
+#ifdef DEBUG
+ /* Most recent time when the given phase ended. */
+ PhaseTimeStamps phaseEndTimes;
+#endif
+
+ TimeStamp creationTime_;
+
+ /* Bookkeeping for GC timings when timingMutator is true */
+ TimeStamp timedGCStart;
+ TimeDuration timedGCTime;
+
+ /* Total main thread time in a given phase for this GC. */
+ PhaseTimes phaseTimes;
+
+ /* Total main thread time for this GC. */
+ TimeDuration totalGCTime_;
+
+ /* Number of events of this type for this GC. */
+ EnumeratedArray<Count, COUNT_LIMIT,
+ mozilla::Atomic<uint32_t, mozilla::ReleaseAcquire>>
+ counts;
+
+ /* Other GC statistics. */
+ EnumeratedArray<Stat, STAT_LIMIT, uint32_t> stats;
+
+ /*
+ * These events cannot be kept in the above array, we need to take their
+ * address.
+ */
+ struct {
+ uint32_t nursery;
+ uint32_t tenured;
+ } allocsSinceMinorGC;
+
+ /* Total GC heap size before and after the GC ran. */
+ size_t preTotalHeapBytes;
+ size_t postTotalHeapBytes;
+
+ /* GC heap size for collected zones before GC ran. */
+ size_t preCollectedHeapBytes;
+
+ /*
+ * If a GC slice was triggered by exceeding some threshold, record the
+ * threshold and the value that exceeded it. This happens before the slice
+ * starts so this is recorded here first and then transferred to SliceData.
+ */
+ mozilla::Maybe<Trigger> recordedTrigger;
+
+ /* GC numbers as of the beginning of the collection. */
+ uint64_t startingMinorGCNumber;
+ uint64_t startingMajorGCNumber;
+ uint64_t startingSliceNumber;
+
+ /* Records the maximum GC pause in an API-controlled interval. */
+ mutable TimeDuration maxPauseInInterval;
+
+ /* Phases that are currently on stack. */
+ Vector<Phase, MAX_PHASE_NESTING, SystemAllocPolicy> phaseStack;
+
+ /*
+ * Certain phases can interrupt the phase stack, eg callback phases. When
+ * this happens, we move the suspended phases over to a sepearate list,
+ * terminated by a dummy PhaseKind::SUSPENSION phase (so that we can nest
+ * suspensions by suspending multiple stacks with a PhaseKind::SUSPENSION in
+ * between).
+ */
+ Vector<Phase, MAX_SUSPENDED_PHASES, SystemAllocPolicy> suspendedPhases;
+
+ /* Sweep times for SCCs of compartments. */
+ Vector<TimeDuration, 0, SystemAllocPolicy> sccTimes;
+
+ TimeDuration timeSinceLastGC;
+
+ JS::GCSliceCallback sliceCallback;
+ JS::GCNurseryCollectionCallback nurseryCollectionCallback;
+
+ /*
+ * True if we saw an OOM while allocating slices or we saw an impossible
+ * timestamp. The statistics for this GC will be invalid.
+ */
+ bool aborted;
+
+ /* Profiling data. */
+
+ enum class ProfileKey {
+ Total,
+ Background,
+#define DEFINE_TIME_KEY(name, text, phase) name,
+ FOR_EACH_GC_PROFILE_TIME(DEFINE_TIME_KEY)
+#undef DEFINE_TIME_KEY
+ KeyCount
+ };
+
+ using ProfileDurations =
+ EnumeratedArray<ProfileKey, ProfileKey::KeyCount, TimeDuration>;
+
+ bool enableProfiling_;
+ bool profileWorkers_;
+ TimeDuration profileThreshold_;
+ ProfileDurations totalTimes_;
+ uint64_t sliceCount_;
+
+ JSContext* context();
+
+ Phase currentPhase() const;
+ Phase lookupChildPhase(PhaseKind phaseKind) const;
+
+ void beginGC(JS::GCOptions options, const TimeStamp& currentTime);
+ void endGC();
+
+ void sendGCTelemetry();
+ void sendSliceTelemetry(const SliceData& slice);
+
+ void recordPhaseBegin(Phase phase);
+ void recordPhaseEnd(Phase phase);
+
+ void gcDuration(TimeDuration* total, TimeDuration* maxPause) const;
+ void sccDurations(TimeDuration* total, TimeDuration* maxPause) const;
+ void printStats();
+
+ template <typename Fn>
+ void reportLongestPhaseInMajorGC(PhaseKind longest, Fn reportFn);
+
+ UniqueChars formatCompactSlicePhaseTimes(const PhaseTimes& phaseTimes) const;
+
+ UniqueChars formatDetailedDescription() const;
+ UniqueChars formatDetailedSliceDescription(unsigned i,
+ const SliceData& slice) const;
+ UniqueChars formatDetailedPhaseTimes(const PhaseTimes& phaseTimes) const;
+ UniqueChars formatDetailedTotals() const;
+
+ void formatJsonDescription(JSONPrinter&) const;
+ void formatJsonSliceDescription(unsigned i, const SliceData& slice,
+ JSONPrinter&) const;
+ void formatJsonPhaseTimes(const PhaseTimes& phaseTimes, JSONPrinter&) const;
+ void formatJsonSlice(size_t sliceNum, JSONPrinter&) const;
+
+ double computeMMU(TimeDuration resolution) const;
+
+ void printSliceProfile();
+ void printProfileTimes(const ProfileDurations& times);
+};
+
+struct MOZ_RAII AutoGCSlice {
+ AutoGCSlice(Statistics& stats, const ZoneGCStats& zoneStats,
+ JS::GCOptions options, const SliceBudget& budget,
+ JS::GCReason reason, bool budgetWasIncreased)
+ : stats(stats) {
+ stats.beginSlice(zoneStats, options, budget, reason, budgetWasIncreased);
+ }
+ ~AutoGCSlice() { stats.endSlice(); }
+
+ Statistics& stats;
+};
+
+struct MOZ_RAII AutoPhase {
+ AutoPhase(Statistics& stats, PhaseKind phaseKind)
+ : stats(stats), phaseKind(phaseKind), enabled(true) {
+ stats.beginPhase(phaseKind);
+ }
+
+ AutoPhase(Statistics& stats, bool condition, PhaseKind phaseKind)
+ : stats(stats), phaseKind(phaseKind), enabled(condition) {
+ if (enabled) {
+ stats.beginPhase(phaseKind);
+ }
+ }
+
+ ~AutoPhase() {
+ if (enabled) {
+ stats.endPhase(phaseKind);
+ }
+ }
+
+ Statistics& stats;
+ PhaseKind phaseKind;
+ bool enabled;
+};
+
+struct MOZ_RAII AutoSCC {
+ AutoSCC(Statistics& stats, unsigned scc) : stats(stats), scc(scc) {
+ start = stats.beginSCC();
+ }
+ ~AutoSCC() { stats.endSCC(scc, start); }
+
+ Statistics& stats;
+ unsigned scc;
+ mozilla::TimeStamp start;
+};
+
+void ReadProfileEnv(const char* envName, const char* helpText, bool* enableOut,
+ bool* workersOut, mozilla::TimeDuration* thresholdOut);
+
+} /* namespace gcstats */
+
+struct StringStats {
+ // number of strings that were deduplicated, and their sizes in characters
+ // and bytes
+ uint64_t deduplicatedStrings = 0;
+ uint64_t deduplicatedChars = 0;
+ uint64_t deduplicatedBytes = 0;
+
+ // number of live nursery strings at the start of a nursery collection
+ uint64_t liveNurseryStrings = 0;
+
+ // number of new strings added to the tenured heap
+ uint64_t tenuredStrings = 0;
+
+ // Currently, liveNurseryStrings = tenuredStrings + deduplicatedStrings (but
+ // in the future we may do more transformation during tenuring, eg
+ // atomizing.)
+
+ // number of malloced bytes associated with tenured strings (the actual
+ // malloc will have happened when the strings were allocated in the nursery;
+ // the ownership of the bytes will be transferred to the tenured strings)
+ uint64_t tenuredBytes = 0;
+
+ StringStats& operator+=(const StringStats& other) {
+ deduplicatedStrings += other.deduplicatedStrings;
+ deduplicatedChars += other.deduplicatedChars;
+ deduplicatedBytes += other.deduplicatedBytes;
+ liveNurseryStrings += other.liveNurseryStrings;
+ tenuredStrings += other.tenuredStrings;
+ tenuredBytes += other.tenuredBytes;
+ return *this;
+ }
+
+ void noteTenured(size_t mallocBytes) {
+ liveNurseryStrings++;
+ tenuredStrings++;
+ tenuredBytes += mallocBytes;
+ }
+
+ void noteDeduplicated(size_t numChars, size_t mallocBytes) {
+ liveNurseryStrings++;
+ deduplicatedStrings++;
+ deduplicatedChars += numChars;
+ deduplicatedBytes += mallocBytes;
+ }
+};
+
+} /* namespace js */
+
+#endif /* gc_Statistics_h */